Objective: In this study, we prospectively investigated the diagnostic capability of diffusion-weighted magnetic resonance imaging (DWI) in assessing vertebral marrow changes in postmenopausal women with osteoporosis.
Materials and methods: Sixty postmenopausal women (mean age 60.2 ± 6.11 years) underwent both dual-energy X-ray absorptiometry (DEXA) of the spine and MRI. Results were acquired from each patient's L2 to L4, for a total of 180 lumbar vertebrae. Based on bone mineral density (BMD) measurements obtained from DEXA, the vertebrae were divided into three groups as follows: normal (n = 52), osteopenic (n = 92), and osteoporotic (n = 36). DWI of the vertebral body was performed to assess the apparent diffusion coefficient (ADC). The ADC outcomes were compared among the three groups and correlated with BMD.
Results: ADC values (× 10-6 mm2/s) were significantly lower in the osteoporotic group (135.67 ± 44.10) in comparison to the normal group (561.85 ± 190.37) (P = 0.0001). The results showed a positive correlation between ADC and BMD values (r = 0.748, P = 0.0001). In receiver operating characteristic (ROC) analysis, the area under the curve for DWI was 0.912 (P = 0.001). A cut-off value of 400 mm2/s for the diagnosis of osteoporosis; had sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of 90.90%, 83.34%, 88.89%, 93.75%, and 76.93%, respectively.
Conclusion: ADC values correlated positively with BMD in women. DWI can allow quantitative evaluation of bone marrow changes and osteoporosis in postmenopausal women.
Keywords: Apparent diffusion coefficient (ADC); Bone marrow; Bone mineral density (BMD); Diffusion weighted imaging (DWI); Osteoporosis.